Techniques for spinal surgery and attaching constructs to vertebral elements

ABSTRACT

Techniques for spinal surgery include accessing at least one vertebral element of the spinal column. At least one loading member is engaged to the at least one vertebral element. The loading member is allowed to integrate with the bony structure of the vertebral element over time. The integrated loading member is accessed in a second surgical procedure, and can be loaded and/or attached to a construct.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a divisional of U.S. patent application Ser. No.10/219,029 filed on Aug. 14, 2002, now U.S. Pat. No. 7,052,497 which isincorporated herein by reference in its entirety.

BACKGROUND

Several systems and devices are available to provide correction andstabilization of the spine. Such systems and devices can include screwsengaged to the vertebral bodies and configured for engagement withelongated rods or plates that extend along the vertebral bodies. Devicesfor fusing adjacent vertebrae and artificial disc replacement are alsoavailable. Furthermore, nonoperative devices and methods, such asbracing and observation, can be used whenever applicable.

During a spinal surgical procedure, a device can be engaged to avertebra and a load applied thereto to provide a corrective force. Thecorrective load that can be applied to the device can be limited by, forexample, the ability of the device to receive the applied load andremain properly engaged to the bony structure in which it is implanted.In such cases the applied corrective load may cause movement of thedevice relative to the vertebra and the resulting loss of engagement orinterface therebetween, or the corrective load may be limited to preventsuch an occurrence.

There remains a need for spinal surgical techniques for attachingconstructs to one or more vertebral elements that address theseshortcomings in prior procedures.

SUMMARY

There is provided a surgical technique which includes a first surgicalprocedure for engaging a loading member to a bony portion, allowing theloading member to integrate with the bony portion, accessing the loadingmember in a second surgical procedure, and loading the integratedloading member.

There is further provided a surgical technique which includes a firstsurgical procedure for engaging first and second loading members toadjacent bony portions, allowing the first and second loading member tointegrate with the respective bony portions, accessing the first andsecond loading members in a second surgical procedure, and attaching aconstruct to the integrated first and second loading members.

According to one aspect, there is provided a technique for spinalsurgery that includes accessing at least one vertebral element in afirst surgical procedure; engaging a loading member to the at least onevertebral element; allowing the loading member to integrate with thevertebral element; accessing the integrated loading member in a secondsurgical procedure; and applying a load to the integrated loadingmember.

According to another aspect, there is provided a technique for spinalsurgery that includes accessing at least one vertebral element in afirst surgical procedure; engaging a loading member to the at least onevertebral element; allowing the loading member to integrate with thevertebral element; accessing the integrated loading member in a secondsurgical procedure; and attaching a construct to the integrated loadingmember.

According to another aspect, there is provided a technique for spinalsurgery that includes accessing at least one vertebral element in afirst minimally invasive approach; engaging at least one loading memberto the at least one vertebral element; allowing the at least one loadingmember to integrate with the bony structure of the vertebral element;accessing the at least one integrated loading member in a secondminimally invasive approach; and applying a load to the at least oneintegrated loading member.

According to a further aspect, there is provided a technique for spinalsurgery that includes accessing a first vertebral element in a firstsurgical procedure; engaging a first loading member to the firstvertebral element; accessing a second vertebral element in the firstsurgical procedure; engaging a second loading member to the secondvertebral element; allowing the first and second loading members tointegrate with the first and second vertebral elements; accessing theintegrated first and second loading members in a second surgicalprocedure; applying a load to the integrated first and second loadingmembers; and attaching a construct to the integrated and loaded firstand second loading members.

According to another aspect, a technique for spinal surgery is providedthat includes accessing first and second vertebral elements of thespinal column in a first surgical procedure with at least one minimallyinvasive surgical approach to the first and second vertebral elements;engaging a first loading member to the first vertebral element; engaginga second loading member to the second vertebral element; allowing thefirst and second loading members to integrate with the bony structure ofthe respective first and second vertebral elements; accessing theintegrated first and second loading members in a second surgicalprocedure; loading the integrated first and second loading members; andattaching a construct to the integrated first and second loadingmembers.

According to a further aspect, there is provided a spinal surgicaltechnique that includes accessing a number of vertebral elements in afirst surgical procedure; engaging load receiving means to the number ofvertebral elements; allowing the load receiving means to integrate withthe number of vertebral elements; accessing the integrated loadingreceiving means in a second surgical procedure; loading the loadingreceiving means; and attaching a construct to the integrated and loadedload receiving means.

According to another aspect, a technique for spinal surgery is provided.The technique includes accessing first and second vertebral elements ofthe spinal column in a first surgical procedure with at least oneminimally invasive surgical approach to the first and second vertebralelements; engaging a first loading member to the first vertebralelement; engaging a second loading member to the second vertebralelement; providing a temporary support between the first and secondloading members; allowing the first and second loading members tointegrate with the bony structure of the respective first and secondvertebral elements; accessing the integrated first and second loadingmembers in a second surgical procedure; and attaching a construct to theintegrated first and second loading members.

These and other aspects will also be apparent from the followingdescription.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an elevational view in partial section showing intravertebralengagement of loading members to vertebrae of a spinal column segment.

FIG. 2 is the view of FIG. 1 showing integrated loading members attachedto a construct.

FIG. 3 is an elevational view in partial section showing intervertebralengagement of loading members to vertebrae of a spinal column segment.

FIG. 4 is the view of FIG. 3 showing integrated loading members attachedwith a construct.

FIG. 5 is an elevational view in partial section showing intravertebralengagement of loading members to vertebrae of a spinal column segment ina minimally invasive procedure.

FIG. 6 is the view of FIG. 5 showing integrated loading members attachedto a construct.

FIG. 7 is an elevational view in partial section showing intervertebralengagement of loading members to vertebrae of a spinal column segment ina minimally invasive procedure.

FIG. 8 is the view of FIG. 7 showing integrated loading members attachedto a construct.

FIG. 9 is an elevational view in partial section showing intravertebralengagement of loading members to vertebrae of a spinal column segment ina minimally invasive procedure.

FIG. 10 is the view of FIG. 9 showing integrated loading membersattached to a construct in a minimally invasive procedure.

FIG. 11 is an elevational view in partial section showing intravertebralengagement of loading members to vertebrae of a spinal column segment ina minimally invasive procedure.

FIG. 12 is the view of FIG. 11 showing integrated loading membersattached to a construct in a minimally invasive procedure.

FIG. 13 is an elevational view in partial section showing intervertebralengagement of loading members to vertebrae of a spinal column segment ina minimally invasive procedure.

FIG. 14 is the view of FIG. 13 showing integrated loading membersattached to a construct positioned therebetween.

DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS

For the purposes of promoting an understanding of the principles of theinvention, reference will now be made to the embodiments illustrated inthe drawings and specific language will be used to describe the same. Itwill nevertheless be understood that no limitation of the scope of theinvention is hereby intended. Any such alterations and furthermodifications in the illustrated devices, and any such furtherapplications of the principles of the invention as illustrated hereinare contemplated as would normally occur to one skilled in the art towhich the invention relates.

The present invention provides systems and techniques for correcting ortreating spinal deformities and/or conditions. The systems andtechniques include one or more loading members that can be engaged toone or more vertebral elements. The one or more loading members areallowed to integrate with the tissue of the one or more vertebralelements, and thereafter loaded and engaged to a construct. By applyingthe load to integrated loading members, the possibility of undesirablemotion, loss of correction, or loss of fixation of the loading memberwith the vertebral element is minimized.

Referring to FIG. 1, there is shown a spinal column segment 20 insection including a first vertebral element 22 and a second vertebralelement 24. First vertebral element 22 is spaced from second vertebralelement 24 by a disc space 26. First vertebral element 22 and secondvertebral element 24 are accessed in spinal surgery for engagement of afirst loading member 50 to first vertebral element 22 and a secondloading member 60 to second vertebral element 24. First loading member50 includes a bone engagement portion 54 embeddable in or contactablewith the bony structure of first vertebral element 22 to secure loadingmember 50 thereto. Second loading member 60 includes a bone engagementportion 64 embeddable in or contactable with the bony structure ofsecond vertebral element 24 to secure second loading member 60 thereto.

It is contemplated that first loading member 50 and second loadingmember 60 can be configured to integrate with the bony structure of therespective first and second vertebral elements over time. For example,first and second loading members 50, 60 can be provided with any one orcombination bone integration features along at least a portion ofengagement portions 54, 64. Such bone integration features may include,for example, a hollow interior, one or more receptacles, one or morechambers, a porous coating, or exterior surface features. Theintegration features should allow bone to at least partially grow into,adhere to, attach, resorb and/or form with the engagement portions 54,64 to integrate loading members 50, 60 to the bony and/or soft tissuestructure of the respective vertebral elements 22, 24.

First and second loading members 50, 60 can also include bone growthmaterial and/or bone growth facilitators. For example, a bone growthinducing material, such as a sponge, matrix, and/or other carrierimpregnated with a protein such as BMP (bone morphogenic protein) and/orLMP (LIM mineralization protein) can be placed within, upon and/oraround the loading members 50, 60. A cap or plug 56 can be provided, ifnecessary, and engaged to the loading members 50, 60 to retain bonegrowth material within the loading member to which it is engaged. Cap orplug 56 can be temporary or permanent. After engagement of loadingmembers 50, 60 the access to the first and second vertebral elements canbe surgically closed.

After integration has been obtained, loading members 50, 60 are accessedin a second surgical procedure for attachment of a construct 70 thereto.Construct 70 can extend between and interconnect the loading members, asshown in FIG. 2. In the illustrated embodiment, first loading member 50is provided with a construct attachment portion 52, and second loadingmember 60 is provided with a construct attachment portion 62.

It is contemplated that the construct attachment portions discussedherein, such as attachment portion 52, 62, can be configured to attachby engaging, retaining, clamping, fastening, holding, contacting,securing or otherwise maintaining the construct to the respectiveloading member. The attachment portions can be separately attached tothe loading members during the first surgical procedure or during thesecond surgical procedure. The attachment portions can be attached tothe loading members after placement of the construct around a portion ofthe loading members extending from the vertebral elements. It is furthercontemplated that the construct can be supported entirely or partiallyby the attachment portions. It is also contemplated that the attachmentportions could be integrally formed with the loading members.

For the second surgical procedure, it is contemplated that loadingmembers 50, 60 will have integrated with the bony or tissue structure40, 42 of vertebral elements 22, 24, and can have sufficient loadcarrying capabilities to withstand loading to correct or treat a spinaldeformity or condition associated with spinal column segment 20. Varioustechniques are contemplated that can be employed to determine whenand/or if integration has been achieved for performance of the secondsurgical procedure. Such techniques include, for example, awaiting thepassage of a certain period of time, which can be based on knownintegration rates, experience, and/or anatomical studies. For example,it is contemplated that the passage of time may extend from a few weeksto several months before the second surgical procedure is performed.Integration of the loading members can also be based in whole or in parton the evaluation of radiographic, fluoroscopic or other imaginginformation taken of the loading members in situ.

The integrated loading members 50, 60 can be subjected to externalloading in the second surgical procedure that can be greater than theloading that could applied pre-integration. Since integrated loadingmembers 50, 60 can be subjected to higher initial loading, the desiredsurgical result may be achieved more efficiently and/or more effectivelythan if the loading members 50, 60 were loaded pre-integration. Forexample, in the second surgical procedure, compression loading 72 can beapplied to the integrated loading members 50, 60, and construct 70attached to the integrated, loaded loading members 50, 60. It is furthercontemplated that distraction loading 74 could be applied to theintegrated loading members 50, 60, and construct 70 attached to theintegrated, loaded loading members 50, 60. In either case, the loadingis maintained with the attached construct 70 so that the desiredsurgical result can be achieved.

On specific application can be directed to the treatment of scoliosis.In such treatment, growth along the long or convex side of spine can bearrested by applying and maintaining a compression load between multipleloading members engaged to vertebral elements along the convex side ofthe spine. With integrated loading members, greater restraint to growthof the convex side of the spine can be provided, facilitating correctionthe scoliosis.

In another specific application, one or more interbody fusion devicescan be inserted into disc space 26 in the second surgical procedure. Acompression load can be applied to integrated loading members 50, 60 andmaintained on the interbody fusion device(s) with construct 70 tofacilitate fusion of the adjacent vertebral elements 22, 24. In afurther specific application, disc space 26 can be collapsed, and adistraction load 74 applied directly to integrated loading members 50,60 to restore the disc space height between vertebral elements 22, 24.The restored disc space height can be maintained by attaching construct70 to the distracted, integrated loading members 50, 60.

It is further contemplated that more than one loading member can beprovided in each vertebral element, and that more than two vertebralelements can be integrated with loading members. It is furthercontemplated that construct 70 can be configured for attachment withmultiple loading members at each vertebral element, and can also beconfigured to extend along multiple vertebral elements, including threeor more vertebral elements.

Referring to FIG. 3, there is further shown spinal column segment 20with a third vertebral element 28 and a disc space 30 between secondvertebral element 24 and third vertebral element 28. First vertebralelement 22 and second vertebral element 24 are accessed in a firstsurgical procedure for engagement of a first loading member 80 in discspace 26. Second vertebral element 24 and third vertebral element 28 arealso accessed in a first surgical procedure for engagement of a secondloading member 90 in disc space 30. First loading member 80 includes abone engagement portion 84 embeddable in or contactable with the bonystructure of first vertebral element 22 and second vertebral element 24to secure loading member 80 thereto. Second loading member 90 includes abone engagement portion 94 embeddable in or contactable with the bonystructure of second vertebral element 24 and third vertebral element 28to secure second loading member 90 thereto.

It is contemplated that first loading member 80 and second loadingmember 90 are configured to integrate with the bony structure of therespective vertebral elements over time. For example, first and secondloading members 80, 90 can be provided with any one or combination boneintegration features along at least a portion of engagement portions 84,94. Such integration features may include, for example, a hollowinterior, one or more receptacles, one or more chambers, a porouscoating, or exterior surface features. The integration features allowbone to at least partially grow into, adhere to, attach, resorb and/orform with engagement portions 84, 94 to integrate loading members 80, 90to the bony structure of the respective adjacent vertebral elements.

First and second loading members 80, 90 can also include bone growthmaterial and/or bone growth facilitators. For example, a bone growthinducing material, such as a sponge, matrix, and/or other carrierimpregnated with a protein such as BMP (bone morphogenic protein) and/orLMP (LIM mineralization protein) can be placed within, upon and/oraround the loading members 80, 90. A temporary cap or plug can beprovided, if necessary, and engaged to the loading members 80, 90 toretain bone growth material within the loading member duringintegration.

After integration has been obtained with the bony or tissue structure40, 42, loading members 80, 90 are accessed in a second surgicalprocedure for attachment of a construct 100. Construct 100 can extendbetween and interconnect the loading members 80, 90, as shown in FIG. 4.It is contemplated that loading members 80, 90 will have integrated withthe bony structure of the adjacent vertebral elements and will withstandloading to be applied thereto to correct or treat a spinal deformity orcondition associated with spinal column segment 20. It is furthercontemplated that more than one loading member can be provided in eachdisc space, and that more than two vertebral levels can be integratedwith loading members. It is further contemplated that construct 100 canbe configured for attachment with multiple loading members at eachvertebral level, and can also be configured to extend along multiplevertebral levels, including three or more vertebral levels.

In the illustrated embodiment, loading member 80 is provided withconstruct attachment portion 82 that can be attachable to or integrallyformed with loading member 80. Attachment portion 82 can be attached toloading member 80 in either the initial insertion procedure of loadingmembers 80, 90, or in the second procedure for loading loading members80, 90 and attaching construct 100. Similarly, loading member 90 isprovided with construct attachment portion 92 that can be attachable toor integrally formed with loading member 90. Attachment portion 92 canbe attached to loading member 90 in either the initial insertionprocedure or in the second procedure for loading loading members 80, 90and attachment of construct 100.

The integrated loading members 80, 90 can be subjected to externalloading in the second surgical procedure that can be greater than theloading that could applied pre-integration. Since integrated loadingmembers 80, 90 can be subjected to higher initial loading, the desiredsurgical result may be achieved more efficiently and/or more effectivelythan if the loading members 80, 90 were loaded pre-integration. Forexample, in the second surgical procedure, compression loading 102 canbe applied to the integrated loading members 80, 90, and construct 100attached to the integrated and loaded loading members 80, 90. It isfurther contemplated that distraction loading 104 could be applied tothe integrated loading members 80, 90, and construct 100 attached to theintegrated and loaded loading members 80, 90.

For the loading members discussed herein, it is contemplated that theloading applied thereto can be any one or combination of compressionloading, distraction loading, tension loading, torsional loading, andlateral loading. The loading can be applied with an instrumentengageable to the integrated loading members and configured to apply thedesired loading thereto in the second surgical procedure. For example, adistraction or compression instrument could be engaged to the integratedloading members, the desired loading applied to the integrated loadingmembers, and the construct attached to the loaded, integrated loadingmembers to post-operatively maintain all or a portion of the appliedloading.

It is also contemplated that loading could be applied to the integratedloading members through the construct. For example, the construct couldbe tensioned and then attached to the integrated loading members in itstensioned state. The tensioned construct would apply a post-operativecompression load between the integrated loading members. In anotherexample, the construct could compressed, positioned between, andattached to the integrated loading members. The compressed constructwould exert a post-operative distraction load between the loadingmembers. In another example, the construct could be attached to theloading members, and configured or thereafter altered to apply a load tothe loading members. The construct could be made from shape memorymaterial, elastic material, or other material in which its properties,shape, form, size or other feature could be configured or altered toload the loading members.

Referring to FIG. 5 there is shown spinal column segment 20 withvertebrae 22, 24, 28 below skin 32 and tissue 34. Vertebrae 22, 24 and28 can be accessed in a minimally invasive surgical approach forengagement of loading members 110, 120 and 130 thereto. For example, aretractor sleeve 170 can be inserted into a dilated path through skin 32and tissue 34 to provide access therethrough to respective ones of thevertebrae 22, 24, 28. First loading member 110 is shown adjacent theproximal end of sleeve 170 before intravertebrally engaging engagementportion 114 to vertebra 22. Second and third loading members 120, 130include engagement portions 124, 134, respectively, intravertebrallyengaged with vertebrae 24, 28.

In one specific embodiment, loading members 110, 120, 130 are insertedin a minimally invasive surgical procedure such as can be performed withthe METRx™ Surgical System marketed by Medtronic Sofamor Danek. Otherminimally invasive surgical systems, procedures, and/or approaches forinserting the loading members and/or the constructs are alsocontemplated.

As shown in FIG. 6, loading members 110, 120, 130 have integrated withthe bony structure 40, 42, 44 of vertebrae 22, 24 and 28, respectively.Loading members 110, 120, 130 are accessed in a second surgicalprocedure, and construct 140 can be attached to respective ones of theattachment portions 112, 122, 132 of loading members 110, 120, and 130.In one embodiment, attachment of construct 140 includes engagingcoupling members 116, 126, 136 to respective ones of the attachmentportions 112, 122, 132 to attach construct 140 thereto.

Various forms for the attachment portions discussed herein arecontemplated. For example, with respect to attachment portions 112, 122,132, there could include a threaded stem around with construct 140 canbe placed, and coupling members 116, 126, 136 could be engaged to thethreaded stem to attach construct 140 thereto. In another example,attachment portions 112, 122, 132 could include a passage sized toreceive construct 140 therein, and coupling members 116, 126, 136 couldbe engaged to the respective attachment portions within or about thepassage to attach construct 140 thereto. Coupling members 116, 126, 136can be, for example, set screws, nuts, caps, clamps, wedges, retainingmembers or other devices capable of engaging either one or both ofattachment portions 112, 122, 132 and construct 140 to attach construct140 to loading members 110, 120, 130.

Referring to FIG. 7 there is shown spinal column segment 20 withvertebrae 22, 24, 28 below skin 32 and tissue 34. The disc spaces 26, 30between adjacent ones of vertebrae 22, 24 and 28 can be accessed in aminimally invasive surgical approach for engagement of loading members150, 160 thereto. For example, retractor sleeve 170 can be inserted intoa dilated path through skin 32 and tissue 34 to provide accesstherethrough to respective ones of the disc spaces 26, 30. First loadingmember 150 is shown adjacent the proximal end of sleeve 170 beforeintervertebrally engaging engagement portion 154 of loading member 150with vertebrae 22, 24 in disc space 26. Second loading member 160includes engagement portion 164 intervertebrally engaged with vertebrae24, 28 in disc space 30.

The vertebrae can be prepared to receive the loading member to beengaged thereto by removing or cutting material, reaming, drilling,and/or tapping holes or receptacles in the bony structure or soft tissuestructure of the vertebrae. In one specific embodiment, loading members150, 160 are inserted in a minimally invasive surgical procedure such ascan be performed with the METRx™ Surgical System marketed by MedtronicSofamor Danek. Other minimally invasive surgical systems, procedures,and/or approaches for inserting the loading members and/or theconstructs are also contemplated.

As shown in FIG. 8, loading members 150, 160 have integrated with thebony structure 40, 42 between vertebrae 22 and 24 and between vertebrae24 and 28, respectively. Loading members 150, 160 are accessed in asecond surgical procedure, and construct 180 is attached to respectiveones of the attachment portions 152, 162 of loading members 150, 160. Asdiscussed above with respect to coupling members 116, 126, 136, couplingmembers 156, 166 can be coupled to respective ones of the attachmentportions 152, 162 to secure construct 180 to the loading members.

In minimally invasive approaches employing a micro-incision or sleeve,such as retractor sleeve 170, viewing of the spinal column segment canbe performed by any one or combination of placing an endoscope throughthe incision or sleeve, microscopically viewing the surgical sitethrough incisions or the sleeve, endoscopically or microscopicallyviewing the surgical site through a second portal to the spinal columnsegment, and through imaging systems, including fluoroscopic,radiographic, and stereotactic systems.

Referring to FIG. 9 there is shown spinal column segment 20 withvertebrae 22, 24 below skin 32 and tissue 34. Each of the vertebrae 22,24 can be accessed in a minimally invasive surgical approach forengagement of loading members 200, 210 thereto. For example, retractorsleeve 170 can be inserted into a dilated path through skin 32 andtissue 34 to provide access therethrough to each of the vertebrae 22, 24through a single sleeve. First loading member 200 includes an engagementportion 204 and can be engaged to vertebra 22 through sleeve 170. Sleeve170 can be repositioned through skin 32 and tissue 34, as shown indashed lines, for access to vertebra 24. Second loading member 210includes engagement portion 214 that can be engaged to vertebra 24.

As shown in FIG. 10, loading members 200, 210 have integrated with thebony structure 40, 42 of vertebrae 22, 24, respectively. Loading members200, 210 are accessed in a second surgical procedure, and construct 230is attached to respective ones of the attachment portions 202, 212 ofloading members 200, 210. Coupling members or the like can be engaged toloading members 200, 210 and/or attached to construct 230 to attachconstruct 230 to the integrated loading members 200, 210.

In FIG. 10, construct 230 is mounted to a minimally invasive constructinsertion instrument, such as the SEXTANT™ Percutaneous Spinal Systemmarketed by Medtronic Sofamor Danek. Instrument 220 includes a firstextension 222 coupled to first loading member 200 and a second extension224 coupled to second loading member 210. Extensions 222, 224 can bepercutaneously guided for coupling with the respective loading member,positioned through a retractor sleeve aligned with the respective onesof loading members 200, 210, or the surgical site can be opened andretracted for insertion and coupling of the extensions to integratedloading members 200, 210. A construct inserter 225 is pivotally mountedto the extensions 222, 224. Construct inserter 225 includes a body 228and an arm 226 extending from body 228. Arm 226 can be curved to followan arc 232 along which construct 230 is swung by pivoting inserter 225about the extensions 222, 224. Construct 230 can be a rod, tether, plateor other element configured to extend between and interconnect loadingmembers 200, 210.

To insert construct 230, inserter 225 is pivoted along path 232 topercutaneously introduce construct 230. Inserter 225 is further pivotedto advance construct 230 to a location adjacent loading members 200,210. Loading members 200, 210 can be provided with attachment portions202, 212 adapted to receive construct 230, or around which construct 230can be positioned, or that construct 230 can be positioned adjacent to.For example, attachment portions 202, 212 can be in the form of a headof a multi-axial screw with a passage sized to receive construct 230 andinternally threaded to receive a set screw to attach construct 230 inthe head, such as is provided with the M8™ multi-axial screw marketed byMedtronic Sofamor Danek.

Before or after introduction of construct 230, loading members 200, 210can be loaded through extensions 222, 224. For example, a compressionload 234 or distraction load 236 can be applied to extensions 222, 224coupled to loading members 200, 210. Construct 230 can then be inserted,if not already inserted, and attached to each of the loading members200, 210 while the loading members are maintained in their loadedcondition.

Referring to FIG. 11 there is shown spinal column segment 20 withvertebrae 22, 24 below skin 32 and tissue 34. Each of the vertebrae 22,24 can be accessed in a minimally invasive surgical approach forengagement of loading members 200, 210 thereto. For example, retractor250 can be inserted through skin 32 and tissue 34 to provide accesstherethrough to each of the vertebrae 22, 24. Retractor 250 can includefirst and second portions 252, 254 having a reduced size configurationfor insertion of retractor 250, and portions 252, 254 can be expanded ormoved away from one another after insertion to provide access to each ofthe vertebrae 22, 24 through an enlarged working channel.

As shown in FIG. 12, loading members 200, 210 have integrated with thebony structure 40, 42 of vertebrae 22, 24, respectively. Loading members200, 210 are accessed in a second surgical procedure, and construct 260is attached to respective ones of the attachment portions 202, 212 ofloading members 200, 210. Retractor 250 could be employed and expandedto simultaneously access integrated loading members 200, 210. Couplingmembers or the like can be coupled to attachment portions 202, 212and/or to construct 260 to attach construct 260 to loading members 200,210.

Before or after introduction of construct 260 through retractor 250,integrated loading members 200, 210 can be loaded through extensionscoupled thereto, through an instrument coupled to loading members 200,210, or through construct 260. For example, a compression load 262 ordistraction load 264 can be applied to the integrated loading members200, 210. Construct 260 can then be inserted and/or engaged to each ofthe loading members 200, 210 while the loading members are maintained intheir loaded condition.

Other minimally invasive access instruments are contemplated. In theembodiment illustrated in FIGS. 11 and 12, retractor 250 includes firstand second portions 252, 254 pivotally coupled at proximal end 256 toincrease the size of distal end 258 to access each of the vertebrae 22,24. Other examples include inflatable or resiliently expandableretractors, or retractors having first and second portions, oradditional portions, mounted at their proximal ends to a linkagemechanism and movable along the linkage mechanism to retract tissue toaccess the surgical site.

Referring to FIG. 13 there is shown spinal column segment 20 withvertebrae 22, 24. Each of the vertebrae 22, 24 can be accessed in aminimally invasive or open surgical approach for engagement of loadingmembers 300, 310 thereto. Loading member 300 is positioned adjacent toor in engagement with the endplate of upper vertebra 22 in disc space26, and loading member 310 is positioned adjacent to or in engagementwith the endplate of lower vertebra 24 in disc space 26. Vertebrae 22,24 can be distracted, if necessary to provide a sufficient disc spaceheight between vertebrae 22, 24 for positioning of loading members 300,310 therein. To prevent disc space 26 from collapsing, a temporaryspacer 320 can be positioned between loading members 300, 310.

As shown in FIG. 14, loading members 300, 310 have been allowed tointegrate with the bony structure 40, 42 of vertebrae 22, 24,respectively, while temporary spacer 320 prevent the disc space fromcollapsing. Loading members 300, 310 are accessed in a second surgicalprocedure, and temporary spacer 320 removed. A distraction load can thenbe applied to directly to loading members 300, 310, or directly to thevertebral bodies 22, 24, to provide a desired disc space height betweenvertebrae 22, 24. Construct 330 can then be positioned between loadingmembers 300, 310 to maintain disc space 26 at the desired disc spaceheight. With construct 330 positioned therebetween, integrated loadingmembers 300, 310 are subjected to the loading necessary to maintain discspace 26 at the desired disc space height with construct 330. Thepotential for subsidence into the adjacent vertebrae and/or movement ofloading members 300, 310 along the adjacent endplate is reduced oreliminated since loading members 300, 310 have integrated with theadjacent vertebrae 22, 24

In the embodiment of FIGS. 13, 14, loading members 300, 310 can beplate-like elements positioned along the endplates of vertebrae 22, 24.Loading members 300, 310 can include spikes, projections, bone screws,anchors, ridges, teeth, holes, or other features that extend into therespective adjacent vertebrae 22, 24, and/or be made from material whichintegrates with the endplates of vertebrae 22, 24. Loading members 300,310 can provide endplate replacement or reconstruction for subsequentloading of the vertebrae after integration of loading members 300, 310.Loading members 300, 310 can also be L-shaped and have a portion (notshown) extending along the exterior surface of the respective adjacentvertebra in addition to the portion of the loading member positionedalong the endplate of the adjacent vertebra.

Temporary spacer 320 can be a block of material positioned betweenloading members 300, 310 having sufficient rigidity to prevent discspace 26 from collapsing beyond desired limits. Temporary spacer 320 canbe attached to loading members 300, 310 with screws, anchors, aninterface between the components, or other arrangement permittingsubsequent removal of temporary spacer 320.

Construct 330 can be an articulating disc, artificial disc, artificialnucleus or other interbody device capable of maintaining the restoredthe disc space height and preserving segmental motion. Construct 330 canbe comprised of material including any one or combination ofcharacteristics, including inflatable, flowable, hydratable, expandable,compressible, and/or elastic material. Construct 330 could also be adistraction spacer inserted between integrated loading members 300, 310to restore the disc space height by separating loading members 300, 310and thus vertebrae 22, 24. Construct 330 could also be positioned in analready distracted disc space between loading members 300, 310.Construct 330 could be configured and/or be comprised of material thatpermits bony fusion between vertebrae 22, 24.

As discussed herein, the loading members can be engaged intervertebrallyor intravertebrally to the one or more vertebral elements. It iscontemplated that loading members can be engaged intervertebrally andintravertebrally with vertebral elements in the same surgical procedure.The loading members can include any one or combination of features tointegrate the loading member with tissue structure of the vertebralelements. The loading members can include material therein and/orincorporated therewith to promote or accelerate bone growth. The loadingmembers can provide solid bony attachment to or between vertebralelements of the spinal column segment. The loading members haveapplication in, for example, the correction of spinal deformities; thetemporary or permanent stabilization of a segment of the spinal column;the temporary or permanent rigid fixation of bone; the temporary orpermanent flexible fixation of bone; as a buttress for bone grafts,artificial discs or fusion devices for the spine; for application andmaintenance of a compression load or distraction load on a spinal columnsegment; and/or for fusionless scoliosis surgery, for example.

The vertebral elements can be an anterior portion of a vertebral body,the endplates of a vertebral body or of adjacent vertebral bodies, orany of the posterior elements of the vertebral body, including thefacets, pedicle, and spinous or transverse processes. The vertebralelements can also be tissue elements associated with the vertebralbodies, such as annulus tissue or ligament tissue.

The loading members can be provided in the form of a screw, bolt,staple, wedge, spike, spacer, cage, anchor, hollow body, solid body,plate, or other form. The loading members can be provided with a boneengagement portion positionable in the vertebral element or betweenvertebral elements for integration with the bony structure. The boneengagement portion of the loading members can include threads, nothreads, smooth surfaces, splines, teeth, nubs, knurlings, spikes,barbs, or other bone engaging projections therealong to engage theadjacent bony tissue. The bone engagement portion of the loading memberscan have an overall shape that is any one or combination of cylindrical;frusto-conical; tapered; cuboid; rectangular; plate-like shape withconvex surfaces, concave surfaces, and/or L-shaped; or any other overallshape suitable for a loading member. The bone engagement portion of theloading members can have a cross-sectional shape that is polygonal,square, rectangular, circular, oval, elliptical, multiple curved andlinear segments or any other cross-sectional shape suitable for aloading member. The bone engagement portion of the loading members canbe hollow or solid, and provided with any one or combination offenestration openings, cannulations, multiple chambers, recesses,cavities, pits, receptacles or the like to receive bone growth.

The loading members can be provided with a configuration suitable forattachment of a construct, or for attachment to a device to which aconstruct is engaged. For example, the loading members can be integrallyformed with an attachment portion to which the construct is engaged. Theloading members can also have an attachment portion coupled thereto by,for example, internally threading the attachment portion to the loadingmember; externally threading the attachment portion to the loadingmember; clipping, clamping, interlocking, slidingly receiving,frictionally fitting, welding, gluing, bayonet locking, or otherwisesecuring the attachment portion to the loading member. The loadingmembers can be provided with an attachment portion configured forengagement with an insertion instrument, or configured for engagementwith an instrument for driving the loading member into engagement withthe vertebral element. The loading members could also be configured sothat the proximal end of the bone engagement portion could be engaged byan insertion tool.

The attachment portion of the loading members can be configured so thatthe construct could be placed over, around, within, between, along,and/or through the attachment portion. Coupling members can be usedcoupled to the construct to the attachment portion. The attachmentportions could also be configured to attach to one or both of theloading member and the construct after the construct has been placedadjacent to or secured to the loading member.

The loading members can be fabricated in whole or in part from anybiocompatible material, including synthetic or natural autograft,allograft or xenograft tissues, and can be resorbable or non-resorbablein nature. Examples of tissue materials include hard tissues, connectivetissues, demineralized bone matrix and combinations thereof. Furtherexamples of resorbable materials are polylactide, polyglycolide,tyrosine-derived polycarbonate, polyanhydride, polyorthoester,polyphosphazene, calcium phosphate, hydroxyapatite, bioactive glass, andcombinations thereof. Further examples of non-resorbable materialsinclude carbon-reinforced polymer composites, shape-memory alloys,titanium, titanium alloys, cobalt chrome alloys, stainless steel,ceramics and combinations thereof.

Constructs can be used to treat a spinal deformity or condition byattaching at least one construct to one or more integrated loadingmembers subjected to loading conditions. A wide variety of surgicalapproaches and techniques are contemplated for accessing the spinalcolumn to engage loading members to vertebral elements, and forattaching and loading the integrated loading members. Such techniquesinclude open surgical techniques in which skin and tissue are retractedto expose the spinal column, and minimally invasive surgical techniques.The surgical approach to the spinal column segment may also be any oneor combination of anterior, lateral, posterior, postero-lateral, orantero-lateral approaches. The surgical approaches may employ open,endoscopic, laparoscopic, thorascopic, microscopic, and surgicalnavigation procedures and combinations thereof. The approaches may bemade to any portion of the spinal column, including the cervical,thoracic, lumbar and sacral regions of the spine.

The loading members described herein can be used for the correction ortreatment of a spinal deformity or condition through attachment of aconstruct to one or more vertebral elements along the affected segmentof the spinal column. It is contemplated that, after the loading membershave integrated with the vertebral elements, the loading members can beaccessed in a second surgical procedure, subjected to the desiredloading, and attached to the one or more constructs. It is contemplatedthat such constructs can include tethering constructs, plate constructs,rod constructs, and/or artificial disc constructs extending between oneor more vertebral elements. Further examples of constructs include, butare not limited to, staples, cables, artificial strands, rods, plates,springs, artificial ligaments, articulating components, artificial discmaterial components, hydrogel components, artificial nucleus components,and combinations thereof. The constructs can be rigid, semi-rigid,flexible, partially flexible, resorbable, non-resorbable, superelastic,or include shape-memory material. Further examples of tether constructsinclude those that are single strand, multiple strands, braided, orcombinations thereof. Tether material can include but is not limited topolymers, such as polyester and polyethylene; superelastic metals, suchas nitinol; shape memory alloy, such as nickel titanium; resorbablesynthetic materials, such as suture material, metals, such as stainlesssteel and titanium; synthetic materials, allograft material; andbioelastomer material.

Aspects of the present invention also have application in correction ofnon-spinal deformities or conditions, such as joint replacement orreconstruction. In such techniques, loading members can be positioned inadjacent bony portions in a first surgical procedure. The loadingmembers are allowed to integrate with respective bony portions. Theintegrated loading members are accessed in a second surgical procedureand subjected to loading to correct a deformity or condition associatedwith the adjacent bony portions. A construct can be attached to theintegrated loading members to maintain or apply corrective loading. Itis further contemplated that a construct configured to restore orprovide motion between the adjacent bony portions could be attached tothe integrated loading members. Examples of such joint replacementtechniques include hip, knee, wrist, ankle, shoulder, elbow, ankle,finger and temporomandibular joint applications.

While the invention has been illustrated and described in detail in thedrawings and foregoing description, the same is to be consideredillustrative and not restrictive in character. All changes andmodifications that come within the spirit of the invention are desiredto be protected.

1. A technique for spinal surgery, comprising: accessing first andsecond vertebral elements in a surgical procedure; engaging at least onefirst loading member to the first vertebral element in the surgicalprocedure; engaging at least one second loading member to the secondvertebral element in the surgical procedure; applying a distraction loadbetween the first and second loading members to distract the first andsecond vertebral elements, wherein the first and second loading membersare attached along one side of the first and second vertebral elementsto correct a scoliotic curvature and wherein applying the distractionload includes: compressing a construct; positioning the compressedconstruct between the first and second loading members; attaching thecompressed construct to the first and second loading members topost-operatively distract the first and second loading members with theconstruct; and maintaining the distraction load on the first and secondloading members with the construct after the surgical procedure iscompleted.
 2. The technique of claim 1, further comprising: allowing thefirst and second loading members to integrate with the bony structure ofthe vertebral element before applying the load to the first and secondloading members; accessing the first and second loading members in asecond surgical procedure; and applying the load to the first and secondloading members in the second surgical procedure.
 3. The technique ofclaim 1, wherein applying the distraction load includes engaging aninstrument to the first and second loading members and applying thedistraction load includes maintaining the distraction load between thefirst and second loading members with the instrument.
 4. The techniqueof claim 3, wherein the instrument includes first and second extensionsattached to respective ones of the first and second loading members. 5.The technique of claim 1, wherein the construct is made from shapememory material.
 6. The technique of claim 1, wherein the first andsecond loading members are attached posteriorly to the first and secondvertebral elements.
 7. A technique for spinal surgery, comprising:accessing first and second vertebral elements in a first surgicalprocedure; engaging at least one first loading member to the firstvertebral element in the first surgical procedure; engaging at least onesecond loading member to the second vertebral element in the firstsurgical procedure, wherein the first and second loading members areattached along one side of the first and second vertebral elements tocorrect a scoliotic curvature; allowing the first and second loadingmembers to integrate with the bony structure of the vertebral elements;accessing the first and second loading members in a second surgicalprocedure after the first and second loading members have integratedwith the bony structure of the vertebral elements; applying adistraction load between the first and second loading members in thesecond surgical procedure to distract the first and second vertebralelements; and maintaining the distraction load on the first and secondloading members after the second surgical procedure is completed.
 8. Thetechnique of claim 7, wherein said construct is compressed to exert thepost-operative distraction force.